interface PageInfo {
  title: string;
  info?: number
}
 
type Page = "home" | "about" | "contact";
type MyRecord<K extends keyof any, T> = {
  [P in K] : T
}
// key : 类型
const x: MyRecord<Page, PageInfo> = {
  about: { title: "about",info:123 },
  contact: { title: "contact" },
  home: { title: "home" },
};	
